Assessment of the uncertainties in temperature change in China during the last century

We have used the China Homogenized Historic Temperature dataset and some long-term station series of the neighbor countries from CRUTEM3, a 5A degrees x5A degrees gridded dataset of monthly mean temperature since 1900, to provide a 107-year record of surface temperature trends and variability. We derived a comprehensive set of uncertainty estimates to accompany the data: measurement and sampling errors, uncertainties in temperature bias estimates, and uncertainties arising from limited observational coverage on large-scale averages have all been estimated. We reanalysed the temperature changes during the period of record. The best estimates of trends for 1900-2006 with uncertainties at 95% confidence range are about 0.09 +/- 0.017A degrees C/decade for the year as a whole, and 0.14 +/- 0.021A degrees C/decade, 0.11 +/- 0.021A degrees C/decade, 0.04 +/- 0.017A degrees C/decade, and 0.07 +/- 0.017A degrees C/decade for winter, spring, summer and autumn respectively. For 1954-2006, the trends for annual, winter, spring, summer and autumn are: 0.26 +/- 0.032A degrees C/decade, 0.35 +/- 0.046A degrees C/decade, 0.25 +/- 0.051A degrees C/decade, 0.16 +/- 0.037A degrees C/decade and 0.22 +/- 0.055A degrees C/decade. Winter saw the most significant warming trend in both 1900-2006 and 1954-2006, while during the most recent period (the satellite era, 1979-2006), all the seasons show similar warming trends: 0.45 +/- 0.13A degrees C/decade, 0.51 +/- 0.11A degrees C/decade, 0.52 +/- 0.16A degrees C/decade, 0.37 +/- 0.10A degrees C/decade and 0.50 +/- 0.16A degrees C/decade for annual, winter, spring, summer and autumn. Trends arising from urbanization have been evaluated as less than 5% of the total warming trend for 1951-2001, so this bias was not removed.